Mobile communications devices are increasingly popular in our society. It is popular to talk on mobile handsets while driving. Many users of mobile handsets would like a simple and convenient way to make a mobile telephone call easily while driving. One attempt to solve this problem is a hands-fee car kit.
A hands-free car kit is an electronic device, which will enable a person to have a conversation on a mobile call without having to hold a mobile handset. The hands-free car kit is a speaker that is loud enough to be heard from several feet away and over the noise of a typical car, combined with a microphone designed to receive a human voice from several feet away. Typically the microphone has some filtering function for filtering out common noises of a car. The hands-free car kit may include a cradle for holding the mobile handset. Many hands-free car kits also supply power to the mobile handset.
Some hands free car kits allow the user to push a button on the unit to operate in privacy mode. Privacy mode allows the user to switch modes so that the mobile handset microphone and speaker are active and the hands-free car kit microphone and speaker are deactivated. This prevents others in the car from hearing what the caller is saying to the person in the vehicle. If the hands-free car kit microphone and speaker are active the unit is in hands-free mode.
While many hands-free car kits are external to the mobile handset, it will be clear to one of skill in the art that a mobile handset could have a hands-free car kit mode. In hands-free car kit mode the mobile handset would have a built in speaker loud enough to be heard from several feet away and a microphone designed to receive a human voice from several feet away.
On many current hands-free car kits with privacy mode, if privacy becomes an issue, the user is required to engage a switch known as a privacy button and pick up the mobile handset for normal use. The reason that a person uses a hands free car kit is to minimize the complexity of operating a mobile handset while driving. Pushing a button to enter and exit privacy mode adds unnecessary complexity to the task of conducting a mobile call while driving.
Some hands-free car kits enter privacy mode automatically when the user picks up the mobile handset by using a mechanical switch. When a mechanical switch is used the switch is typically placed in the cradle, requiring wiring to be placed in the cradle. Additionally, a mechanically switch can more easily become contaminated and fail to function properly.